浅析聚酯生产中二甘醇控制的可行性方法

在聚酯生产中，二甘醇(DEG)不仅影响着无油丝的染色，也影响着熔体强度，只有稳定的生产工艺才能有稳定的DEG含量。为了保证生产中DEG含量的稳定性，从酯化阶段的乙二醇(EG)与对苯二甲酸(PTA)物质的量比、酯化液位、酯化温度等主要影响因素和缩聚阶段DEG生成情况进行分析，找出一种比较有效、快速调整DEG含量的可行性方法。试验证明，调控酯化阶段EG加入量这一方法对控制DEG的生成是可行的。     

影响聚酯切片中二甘醇含量的因素

探讨了 PTA质量、EG/ PTA摩尔比、酯化温度、酯化压力、生产负荷和缩聚真空度等因素对聚酯切片中二甘醇 (DEG)含量的影响。指出要控制 DEG含量 ,必须视生产情况及时采取调整工艺参数 ,调节 EG/ PTA摩尔比 ,降低酯化温度及酯化压力以及提高生产负荷等措施     

半连续直接酯化BHET合成中醚键的生成

对于中小型聚酯生产装置，采用常压半连续操作直接酯化工艺可有效地降低酯化过程中醚键的生成。在酯化过程中ＥＧ／ＰＴＡ的摩尔比及所使用的缩聚催化剂种类对醚键的生成有影响，而原料ＰＴＡ无论以它的ＥＧ浆料形式添加或以干粉状添加入反应体系，对醚键生成规律一致。     

30L反应釜合成工艺对PET中DEG含量的影响

采用30 L反应釜合成聚对苯二甲酸乙二醇酯(PET),研究了温度、压力、原料摩尔比和投料方式对PET中二甘醇(DEG)含量的影响,对比了不同DEG含量的PET的纺丝性能及其纤维的力学性能和染色性能。结果表明:采用加压酯化工艺,酯化温度对PET中DEG含量的影响较小,增加投料乙二醇/对苯二甲酸(EG/TPA)摩尔比或酯化压力均会提高PET切片中的DEG含量;相对于一次性投料加压酯化工艺,连续投料常压酯化工艺合成的PET切片中DEG含量低;随着DEG含量的增加,PET纤维的结晶度和断裂强度降低,纤维的染色深度提高。     

PET生产中二甘醇含量的影响因素分析

在300 t/d聚合装置上,采用德国吉玛公司五釜工艺流程直接酯化连续生产聚对苯二甲酸乙二醇酯(PET),探讨了PET生产过程中二甘醇(DEG)的生成及相关影响因素。结果表明:PET生产中DEG的生成主要发生在酯化Ⅰ阶段;原料质量及工艺条件是DEG含量的主要影响因素;生产中,控制精对苯二甲酸(PTA)粒径在165~195μm、酯化Ⅰ温度260~265℃、酯化Ⅱ温度265~270℃、乙二醇(EG)/PTA摩尔比1.58~1.65、酯化Ⅰ压力65~75 k Pa、生产负荷270~330 t/d,可稳定PET产品中DEG含量;相比锑系催化剂,使用钛系催化剂时,DEG生成量较少。     

不同PET切片固相缩聚主副反应规律研究(Ⅲ)

本文接近于工业生产的装置上对几种不同工艺生产的PET切片的固相缩聚进行了对比研究,指出在固相缩聚中,PET的链增长仍符合普通的二级反应动力学方程,且与文献报道一致。用直接酯化工艺生产的有光切片和半消光切片进行固相缩聚时,其动力学行为相似;用酯交换工艺生产的PET切片进行固相缩聚时,难以得到高分子量的产物;直接酯化中不同TPA/EG配比所得到的PET切片的固相缩聚动力学行为相似。实验还发现,在PET切片的固相缩聚中,羧端基含量有所下降,醚键含量基本不变。这些结果对于为满足不同用途而选择固相缩聚所用的PET切片具有重要意义。     

高负荷下聚酯工艺参数的优化

介绍原 2 0万t/a装置增容到 2 4万t/a时的工艺参数优化。PTA平均粒径 95～ 110 μm ,n(EG) /n(PTA) =2 .6～ 2 .7,酯化液位 63 %～ 64 % ,温度 2 92～ 2 96℃ ;乙二醇锑催化剂 ,稳定EG、DEG量 ,选择TiO2 消光剂 ,滤除凝聚粒子 ;预缩聚温度 2 87～ 2 89℃ ,压力 2 .4～ 2 .8kPa,液位 42～ 48cm ;终缩聚温度 2 90～ 2 91℃ ,压力 2 .5～ 3 .0hPa,液位 60～ 62cm ,搅拌速度 2 .7r/min。     

β-二酮铝和β-二酮酯铝催化合成聚对苯二甲酸乙二醇酯

采用对苯二甲酸(TPA)和乙二醇(EG)为原料,以自制的β-二酮铝和β-二酮酯铝为催化剂经酯化、缩聚,制得聚对苯二甲酸乙二醇酯(PET).探讨了反应条件对合成反应的影响.结果表明:β-二酮酯铝和乙酰丙酮铝优于其他β-二酮铝.EG与TPA的摩尔比为1.2∶1、催化剂的用量为0.5%(与TPA的摩尔比),酯化反应温度为26...     

论四釜PTA法聚酯装置工艺参数控制

根据四釜PTA法聚酯装置生产实际,对酯化段反应、缩聚段反应的参数控制进行分析,结果表明：酯化阶段的酯化率和聚合度与PTA的粒径、停留时间、温度、压力、游离EG浓度有关;缩聚阶段反应与催化剂、温度、液位、搅拌速度及真空度有关。论述了各阶段在不同情况下工艺参数的优化是相互影响的,要协调各参数控制调整,综合考虑相互补偿,对实现聚酯装置的平、稳、优运行有一定的指导作用。     

直接酯化法制备SIPE-EG溶液的工艺研究

以间苯二甲酸-5-磺酸钠(SSIPA)和乙二醇(EG)为主要原料通过直接酯化法制备了间苯二甲酸双羟乙酯-5-磺酸钠(SIPE)溶液,采用单因素试验考察了原料配比,反应温度及反应时间对酯化反应中的SSIPA转化率及SIPE溶液中DEG含量的影响,结果表明,当EG与SSIPA的量比为9.5∶1,反应温度为186℃,反应时间为250 min时所制备的SIPE溶液满足后道纺丝要求。     

Formation of diethylene glycol by dehydration of glycol in the presence of terephthalic acid

The amount of diethylene glycol (DEG) formed as a result of the dehydration reaction of ethylene glycol (EG) in the presence of terephthalic acid (TPA) was measured. It became clear that the amount of DEG formed at the boiling point of EG can be expressed by a regression equation. It was confirmed that by this equation, the amount of DEG formed under the carboxylic end group concentration of 0.0 to 0.6 Eq/kg and the reaction time of 0 to 20 h can be estimated with high accuracy.     

聚酯（PET）反应过程研究：Ⅱ.酯化反应过程动力学研究

对乙二醇和对苯二甲酸直接酯化反应过程的主反应动力学和生成ＤＥＧ副反应的动力学进行了研究，得到了不同温度下的反应速率，进而获取了各反应的活化能和频率因子。     

A mathematical model for computer simulation of a direct continuous esterification process between terephthalic acid and ethylene glycol

To study the effect of potassium titanium oxyoxalate on the esterification reaction of terephthalic acid (TPA) and ethylene glycol (EG) in the first tank reactor of TPA/EG continuous esterification, experiments at various addition rates of potassium titanium oxyoxalate were made in the pilot plant. Potassium titanium oxyoxalate accelerated the esterification reaction of TPA and EG. Also, reaction rate constants of the reaction scheme reported in a previous report were fitted with the experimental results, and the calculated values of physical properties of oligomers obtained from these reaction rate constants showed relatively good agreement with experimentally obtained physical properties of the oligomers. The effect of potassium titanium oxyoxalate on the reaction rate constants was expressed by a set of seven equations: Using the resultant reaction rate constants, the esterification reaction at various addition rates of potassium titanium oxyoxalate were stimulated and the following conclusions drawn:

• 1 Under low pressure close to atmospheric, when the amount of water in the reaction mixture is very low, the decomposition of potassium titanium oxyoxalate proceeds slowly and decomposition can be practically neglected.
• 2 Potassium titanium oxyoxalate accelerates the esterification reaction.
• 2 Potassium titanium oxyoxalate mainly accelerates the main reactions and its effects on side reactions are rather weak. As a result, the higher the addition rate of potassium titanium oxyoxalate, the lower the values of AV and DEG, as is preferable.

     

酯型阳离子染料易染共聚酯纤维的研究 （Ⅰ）共聚酯的合成研究

为了改善ＥＣＤＰ的耐热性，选用耐热性优良的脂肪族聚酯二醇作为第四组分，ＳＩＰＥ为第三组分，采用ＰＴＡ路线进行酯型ＥＣＤＰ合成研究，并利用ＤＳＣ、ＧＰＣ等手段对共聚酯进行性能研究，结果表明：合适的聚合温度为２７５～２８０℃；ＳＩＰＥ使得共聚酯ＤＥＧ生成量增高．熔点降低，低聚体含量升高；加入ＮａＡｃ可以抑制ＤＥＧ生成；加入第四组分，共聚酯Ｔｍ、Ｔｃ、Ｔｇ和－ＣＯＯＨ均有下降．     

聚酯中二甘醇的影响因素及控制方法

讨论了影响切片中二甘醇含量的各种因素。对于聚酯生产中 ,二甘醇主要产生于第一酯化反应这一实际情况 ,提出要控制二甘醇的含量必须结合生产实际 ,及时调整n(EG) /n(PTA)、酯化温度、酯化压力、停留时间等。     

用单管式试验装置研究酯化工艺的影响因素

模拟工业实际生产,在单管试验装置上,研究了不同工艺条件(浆料的n(EG)/n(PTA),反应温度,循环比,反应压力),对PTA直接酯化反应酯化率和副产物乙醛、二甘醇生成的影响。试验表明:调整工艺参数,降低n(EG)/n(PTA)(由2.0降至1.8)、反应温度由285℃降至281.5℃、适当增加循环比,既节约能源又降低单耗。     

Synthesis and properties of UV-curable waterborne unsaturated polyester for wood coating

UV-curable waterborne unsaturated polyesters for wood coatings were prepared. The effects of different polyols and acids on the properties of the UV-curable waterborne unsaturated polyesters were investigated. Several different unsaturated polyester prepolymers were prepared from three different polyols [ethylene glycol (EG), diethylene glycol (DEG), and propylene glycol (PG)] and three different acids [tetrahydrophthalic anhydride (THPAn), terephthalic acid (TPA), and trimellic anhydride (TMAn)]. UV-curable coating materials were formulated from the prepolymers and 2-hydroxy-2-methylphenyolpropane-1-one as a photoinitiator with distilled water as a diluent. Trimethylolpropane diallyl ether was used as an air inhibitor of cure. The dynamic mechanical studies showed the properties of those unsaturated polyesters were well correlated with their glass transition temperature behaviors. It was found that the unsaturated polyester prepared with 60/40 (mol %) TMAn/THPAn and the equimolar mixture of EG, DEG, and PG showed balanced coating properties such as good tensile properties and weatherability, as well as proper viscosity (ca. 2500 cps) when using distilled water as a diluent. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 695–708, 1998     

Alkaline depolymerization of poly(trimethylene terephthalate)

The purpose of this study was to investigate the effects of reaction media, composition, and temperature on the rate of the alkaline depolymerization of poly(trimethylene terephthalate) (PTT). The alkaline depolymerization of PTT was carried out at 160–190°C in ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), ethylene glycol monobutyl ether (EGMBE), diethylene glycol monoethyl ether (DEGMEE), and a mixture of these solvents. During the reaction, PTT was quantitatively converted to disodium terephthalate and 1,3-propanediol. The alkaline depolymerization reaction rate constants were calculated based on the concentration of sodium carboxylate, which was equivalent to the molar amount of sodium hydroxide. The depolymerization rate of PTT was increased by increasing the reaction temperature and by adding ethereal solvents. Moreover, the depolymerization rate was significantly accelerated in the order of EG < DEG < TEG < EGMBE < DEGMEE. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 99–107, 2001